The mechanisms behind rock-weathering processes can provide vital clues for understanding and reconstructing the history of ancient environments and visualizing the physical conditions in which they were formed, especially climatic situations. Thick ancient coverings of weathered material such as laterites are still the most intensively studied to date. However, little is known about the initial stages of weathering, owing to the rare occurrence of well-preserved examples.
As a contribution to the PEGI-PROSE (1) programme, scientists from the IRD, the CNRS and the University of Strasburg (2) are conducting investigations on Mount Cameroon. They have identified some of the mechanisms that operate during the first stages of basalt rock weathering and have postulated a particular weathering rate. For that they have studied interactions between water and rock by analysing the chemical compositions of spring waters arising from rainwater percolation through the rock. This rock undergoes changes in response to the various factors (such as temperature, precipitation rate, vegetation) that prevail. The processes give rise to the formation of secondary minerals such as hydrated silicates.
Mount Cameroon, an active volcano which is also the country’s highest peak (4095 m), was chosen for its geological, geographical and climatic characteristics. It has become a reference site for the study of basaltic rocks in a humid tropical climate. Its volcanic nature, massive form and location on the Atlantic coast offers some extreme and varied conditions of temperature and rainfall (3). The parent-rock consists mainly of basaltic lava flows and pyroclasts (pumice, ash). This type weathers 10 to 100 times more rapidly than the other continental rocks owing to its high glass content and the porosity of the pyroclasts, which makes it possible to study the initial stages of weathering. The recent activity of Mount Cameroon has moreover been well mapped (4) and the oldest lavas date from 11 million years B.P. (Upper Miocene).
Marie Guillaume | alfa
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
Modeling magma to find copper
13.01.2017 | Université de Genève
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction